Coefficient of Heat Transfer in Pool Boiling

Abstract

Heat transfer in pool boiling is much better than that in usual monophase fluid flow. It is said that its mechanism is based on turbulency of boiling bubbles. But a fine point of the mechanism is not very clear. Then author has investigated about the heat transfer in the contact area of a bubble on the heating surface, and has found that its area is the most important part in boiling heat transfer. Therefore it is now necessary to investigate the coefficient of heat transfer in pool boiling in the whole range of heating load. From this standpoint, author analyticaly investigated various mechanisms of heat transfer in pool boiling, especially in saturation, and has found that under high heat load the contact area of bubbles on the heating surface is the main part in boiling heat transfer, and that under low heat load natural convection by bubbles rising from the heating surface is so.